This article argues that the rule of contra proferentem is not applicable to international sales contracts governed by the United Nations Convention on Contracts for the International Sale of Goods (CISG). It further argues that the common recognition of the rule of contra proferentem under the CISG is an instance of a broader phenomenon which it calls ‘internationality overreach’. ‘Internationality overreach’ is the tendency to project onto the provisions of a uniform private law instrument doctrines and concepts which are inaccurately presumed to constitute universally recognised principles of private law or the ‘common core’ of various legal systems. This article demonstrates that internationality overreach disrupts the goals underpinning the harmonisation of commercial law in two ways: first, it undermines uniformity in the application of international conventions; and, second, it leads to outcomes that fall short of the agreement reached by the Contracting States during the drafting process. While this article focuses on the CISG, the argument developed in this article is of equal relevance to other uniform private law conventions which follow the principle of autonomous interpretation.

The integration of sustainable development goals in the international sales contracts of biofuels highlights a new role for international contract law. This article examines how the substantive rules of the UN Convention on International Sale of Goods (CISG) may contribute to the implementation of sustainable development and the applicability of the “sustainability clauses.” The contracting parties, including the final buyers of a global supply chain have the right to demand enforcement of these contractual clauses. However, the CISG is limited as to the legal effects international contracts have for third-parties that benefit or are interested in the sustainable development of biofuels. In this context, the contractual tool used in the international trade of sustainable products becomes not only useful but also indispensable.